#009: Cribsheet
Baby burritos, breastfeeding vs formula, cry it out - a data driven approach for the first months of a baby
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The Book
Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool
by Emily Oster
Introduction
Deciding whats right for your child, your family and for you is the crucial question of parenting. Specially because there's enough conflicting information out there. Using cost/benefit analysis/thinking will help you to make decisions.
The author tried to distill the best studies (leveraged ideally on randomized trials) to take conclusions. For most of the conclusions presented, the author seemed to be very careful in taking correlation as causation in most cases. This is positive.
An early conclusion is that data is only a piece of the puzzle. Your preferences and opinions as a parent are very important (and, many times, according to the author, the most important component). In fact, the data in this books shows that there are no silver bullets nor horribly harmful wrong ways in most decisions we have to do as parents. There are however some proven best practices. This is what you get when you read this book.
Just a note here: I’m not a medic and this is not advice from me. I also may have made mistakes in reading and writing. Please be critical of everything you read including this post.
It goes without saying: please follow the advice of your doctors
In the beginning… Your baby is born
When a baby is born, moms want to stare at their kids all the time.
There are already a few things to witness, do and decide that include baths, circumcision, tests and some weight loss.
On baths, there's no clear evidence for benefits or drawbacks from giving your baby a bath right after birth. It used to be best practice to wash the baby right after birth. But there have been concerns:
Skin to skin contact with the mother helps breastfeeding success
Baby temperature might decrease. This is not backed up by data.
With regards to circumcision, the benefits and costs are quite small and it's mostly dependent on geography and religion. In Europe we normally don't circumcise. In the US, it's quite common but a declining practice.
Circumcision pros
Less UTIs (1% of uncircumcised babies will get a urinary tract infection vs 0.13% of circumcised)
Less risk for phimosis (inability to pull the foreskin back) and penile cancer
Circumcision cons
There's a risk of infection after the procedure. 1.5% result in minor complications.
It can lead to compression of the urethra (meatal stenosis) in very rare cases.
Regarding tests, your baby will do some blood and hearing tests. Hearing loss is a relatively common concern in babies (1 to 3 out of 1000).
There's something called Rooming in, in Baby Friendly Hospitals where the baby is with their mother 24h/day.
Pros: improved breastfeeding success (which is not proven, a randomized trial found no impact on bf success)
Cons: less sleep for the mother. Further one needs to be careful: Bed sharing (co-sleeping) can lead to infant death (SIDS - Sudden Infant Death Syndrome).
Baby weight loss is a completely normal thing.
At the 50th percentile, the average baby will lose 7% of their weight in the first 48 hours
Breastfed babies lose more weight because it takes longer for milk to come out of the breasts, as opposed to formula feeding. Vaginal births or c-sections will also play a part in weight change.
50% of babies will have jaundice. This is because the liver cannot break down bilirubin, a byproduct of breaking down red cells. This bilirubin can accumulate and cause brain damage, although it's very rare. A symptom: skin will turn yellow. But nothing to panic about. If after a test, bilirubin is indeed too high, babies will need phototherapy in a blue light box.
Right after birth
Delay cord cutting has benefits - namely to prevent anemia
Vitamin K shot - prevent bleeding disorders1
After your baby is home
Sleeping and crying
Sometimes there's nothing that you can do: babies will jut cry no matter what you do.
Babies who cry are called colicky. Understanding if your baby is colicky follow the rule of 3: 3 hours a day, > 3 days a week, for more than 3 weeks. 2.2% of babies fit this description although 20% of parents say their child cries a lot. Colic will go away in most cases after 3 months.
Infants crying links to postpartum depression and anxiety. Both parents will need a break. It's fine to leave your baby momentarily to take a shower.
Swaddling (as seen applied above which transforms your baby into the cutest burrito) limits arousals (i.e. baby waking up) as well as it reduces crying.
An interesting fact: when babies sigh, there’s a 50% chance they wake up.
Babies should be sleeping on their backs. Babies who are swaddled and put on their stomach have an increased risk of SIDS (Sudden Infant Death Syndrome)
A possible solution for a crying colicky baby: probiotics is shown to have a reduction in crying with no downsides.
Another solution is changing the baby's formula or the mother's diet if they breastfeed. In the case of the mother's diet, low alergen diet (removing dairy, wheat, eggs, and nuts). Evidence is weak on this. But results can be quick to see in a few days.
Ultimately, babies will cry and there's nothing you can do about it other than managing your own stress.
It's a good practice to keep track of poops, pees and food. But don't overdo it.
The hygiene hypothesis and fevers
We’ve always been told that being exposed to germs early on can build immunity (which is called the hygiene hypothesis). Although evidence is not conclusive, there's reason to believe this.
Most doctors recommend protecting babies from illness in their first 3 months. A fever in babies under 1 month is to be taken seriously. After the baby is 3 months old and had their vaccines, treatment of a a fever is normal.
Recovery after birth
Recovery for women after the birth can be difficult.
In C-sections, the doctor will stitch and healing will follow like any other procedure. In Vaginal births, there might be some tearing, rated from 1 to 4 depending on how extensive it is. 1% to 5% of women will get 3/4 degree tearing.
In the following days there will be bleeding. Peeing might hurt. Pooping might take a few days. The body seems to be adjusting to the trauma.
Women will still look pregnant. After 40 weeks of expanding, things will take some time to get back to normal.
With regards to sex, there should be none until 6 weeks after the birth. Most couples resume sexual activity 8 weeks after the birth. It may take a year to get back to pre birth sex life.
Emotionally, women can also suffer from postpartum depression. A hormone surge can cause baby blues to 10 to 15% of women. Half of these women experience depression during pregnancy. There is the Edinburgh postpartum depression scale which can be useful for self diagnose.
Important to remember: lack of sleep can be a factor for depression. Screen your depression signs and take it seriously.
Breastfeeding
Studies on the benefits of breastfeeding are weird. IQ correlation with breastfeeding is flawed because richer/more educated women have more time to breastfeed. There was one large study in Belarus in the 90s that is useful with 17,000 mother/baby pairs.
These are the demonstrable benefits of breastfeeding:
Other illnesses fell within confidence interval.
There seems to be no proven long term benefits to breastfeeding. Impact on IQ is not proven. Breastfed kids do seem to have higher IQ, but there's no proven causation causation.
Be careful with breastfeeding myths:
BF is not birth control
Weight loss
Post partum depression
Better friendships
In the end mothers who breastfed feel a strong satisfaction in doing so.
The process of breastfeeding
There can be problems breastfeeding, namely with
Latching: the baby sucking on the breast. Over time women learn to feel when there is a good latch. It's good to have your partner around.
Supply: having milk
There's some evidence that skin to skin contact (just after baby is born) improves breastfeeding success.
For most women, breastfeeding is somewhat painful at least early on. But it usually resolves after a few weeks. To help the pain, rubbing breast milk on the nipples can help.
There is no evidence that pacifiers affect breastfeeding. When babies are born, moms product colostrum. After 72 hours of giving birth, milk will "come in" or up. Doctors will sometimes recommend to do a demand feedback loop: i.e. milk pumping right after feeding. May induce the body into thinking more supply is needed. No studies seem to back this.
If you develop oversupply, cold/hot pack can help. Cold cabbage leaves can also help. The only thing advised to not eat while BF is high mercury fish.
It's a myth that cauliflower, beans and broccoli can lead to a colic baby. Drinking should have no effect on milk. Regarding drugs: painkillers top of the counter are ok. Anti depressants are also ok.
Caffeine babies tend to be irritated so careful with coffee.
Women use pumps because
Supply might be underwhelming
Train baby for bottle
Easier management with work
Sleeping
The biggest concern and risk is SIDS, which is the number 1 cause of death in babies in the first year.
The strict medical recommendations to avoid SIDS:
Babies sleep on their backs
Stomach sleeping -> 8x more likely for SIDS
In their own crib (i.e. not in the parents' bed - co-sleeping)
In the parents room
With nothing soft around
Once the baby can rollover on their own, the risk reduces. The risk of co-sleeping is small but non-zero. The risk increases if the mother drinks and smokes.
Risk of SIDS in Co-sleeping - 0.22 deaths per 1000 births
Risk of SIDS in Sleeping - 0.08 per 1000 births
Parents still sometimes prefer co-sleeping as it is more convenient (taking and putting the baby to sleep).
Room sharing is recommended from 6 months up to a year. This might be too much. 90% of SIDS happen in the first 4 months. Letting the baby have their own room can help with their sleep. In fact babies who sleep in their own room after 9 months sleep 45 min more. So moving the baby to their own room from 4 months to 9 months seem like the best decision.
Infants should not have blankets. Also, really avoid sofa sleeping.
Sleeping Duration
There’s very high variability in studies and babies
Babies wake up between 6am and 8am
Earlier bed time equals longer sleep
Work
Working or not (i.e. being a stay-at-home parent) can create tension, guilt and judgement. People should think about how they will want to optimize their adult hours. Parent might not need to work but they might want to and that's important.
Important question: does having a parent at home offer any advantage?
Extensions in maternity leave from 6 months to 1 to 2 years have no proven effect on child outcome (school test or income as adults). This means that parents working full time has the same impact long term wise compared to children who have one parent stay home. In fact, if one parent works, particularly mothers, daughters are shown to more likely to work in the long run.
All in all: working full time does not break your children's future.
Parental leave is important - babies do better. A study in Norway found that 4 months of parental leave led to higher education and wages. The U.S. does not have any federal maternity leave benefits, it's left to the states and companies.
In terms of budgeting, families need to account for couple's salaries and understand:
0-3 years is more expensive
Marginal value of money - you need to think about the utility function and, in this case, it's happiness. If you'd be happier staying home then it's a factor.
If a parent is not home, then you’ll decide to use a day care or a nanny.
The quality of the day care matters. Higher quality day care strongly correlates with better child language development (although there are other confounding features such as family wealth). Ultimately, for child's success, parenting matters more than day care.
How to evaluate a day care? Here’s a table taken out of the book.
Other observations to make in your day care:
Are the adults interacting with the children?
Positive physical contact?
Hitting, speaking badly or negatively are very bad signs
With regards to hiring a nanny, it's harder to evaluate. Use references. Nanny seems to be show better early language cognition vs day care. But kids in day care after 4 years old have better language and cognition outcomes.
Day care times has no effect in parent attachment.
Kids in day care are more likely to get sick. But this creates immunity. Regardless of option, have a plan for when the kid is sick. Because they will get sick a lot.
Sleeping
First think you need to know: Cry it out - a philosophy in child care where you let your child, well, cry it out.
A proven way to sleep train is called extinction (ominous I know..) where you let the child cry it out. There is a tremendous amount of evidence that shows that cry it out really works.
Bed time routine is a good thing. Better sleep is correlated with less mother depression. A study in Sweden showed that "cry it out increased attachment of babies to parents during daytime.
There are studies who question where cry it out is adequate because parents are ignoring a distress call. These tend to be associated with attachment theory. A study was conducted in NZ where cortisol levels for the child and the mother were measured. At the start, the child was crying to sleep, cortisol levels were the same (the mother's and the child's). After 3 days, the baby stopped crying but the cortisol levels stayed the same while the mother's cortisol levels reduced. The study argues that this might be because of lack of attachment.
There is not perfect data. But it is a mistake to say that sleep training is not the safest option.
There are 3 variants of cry it out:
Extinction: just leave the room.
Graduated extinction: come back at increasing length intervals
Extinction with parental presence.
All 3 works. The only thing that matters is consistency. Choose one method and stick to it.
Sleep training can start at 8 to 10 weeks. A plan for sleep training: it depends on the baby.
Introducing solid foods
Children exposed to peanuts are far less likely to be allergic to them at the age of 5 vs children who were not. Early exposure to peanuts seems to be recommended.
Transition to solid foods starts between 4 to 6 months with rice cereal or oat meal. Then, days later, fruits and veggies, one variety at a time every 3 days. A month later, meat. All purée.
This phased out introduction of food helps to triage and correlate potential allergies.
Studies on baby led weaning are limited. No positive or negative outcomes proven so far. One of the fears is that it can lead to chocking, but there's no more risk than tradicional spoon fed.
The reason to wait to 4 months to introduce solid food is physiological (babies cannot eat other types of food)
Mothers who drank a lot of carrot juice during their pregnancy had kids who liked carrots more.
When feeding your child, autonomy supportive prompts work better than coercive prompts. Sentences like "try this hot dog" instead of "eat this or I'm taking your iPad"
Summary:
Offer your very young child a wide verity of foods
Keep offering even if they reject
Don't freak out when they don't eat as much as expected (> 2 yo)
If they don't eat new foods, don't replace with other foods they like
Don't use threads or rewards to coerce to eat.
Cow's milk is forbidden. Cheese and yogurt instead. Cow's milk is not a replacement for breastmilk or formula. It can lead to iron deficiency. Honey is also forbidden. It can lead to botulism.
Development Milestones
Pediatricians use normal distributions to evaluate the development of children
Doctors use lack of development in head movement, rolling over as a proxy for other conditions (like development disorders)
Cerebral Palsy - 1.5 to 3 in 10000
Muscular dystrophy - 0.2 in 1000
No correlation to early walking toy elite athletes. Percentiles are used to diagnose problem and not positive things about the child’s future. They're not used to predict positive traits but rather only problems.
There will be a lot of sick days. Kids get 6 to 8 colds a year.
It's possible that your kid will be sick 50% of the time in winter.
American academy of pediatrics recommends no tv or screen time. In 2019, researchers tried to find if Baby Einstein (a TV program for babies) worked for children 12-15 months-old in learning words. In two groups analyzed (one using DVDs and another not) there were no differences found. The biggest predictor was if the parents read to their children.
So.. Baby Einstein doesn't work.
Sesame street has been found to have positive impact on schools readiness, including vocabulary. Sesame Street also had correlation to not being held back. But this applies to older children and not very young.
Parents use TV as a way to keep children distracted. Does it affect them negatively? the book says yes.
Many research papers correlate TV with bad outcomes. Research suggests that TV under the age of 3 lowers tests scores. However, watching TV after 3 doesn't seem to matter.
Jesse, the author’s husband, did research on whether TV impacted children. They found no impact on test scores.
Overall, we have no idea what's the impact.
When you don't have the data, you have to use reason
Richard Feynman
Obviously, 80% of the day watching TV is bad. There’s an opportunity cost of time: if the alternative to watching 1 hour of TV is angry parents, then TV in small doses should be fine.
Just remember:
Your 0-2 yo cannot learn from TV
3-5 can but pay attention to what they watch.
Language development
Researchers found a way to measure vocabulary size in children. Boys tend to develop slower than girls. At 14 months, >50th percentile explodes in productive vocabulary.
It seems that being a late talker has negative correlation with academic performance. Being an early talker also seems to be correlated with better performance.
Potty training
Potty training is happening later, compared to older generations of humans.
The only benefit to potty training earlier is not changing as many diapers. The earlier you start, the longer it takes you to complete. On average, for kids born after 2009, potty training completion is at 32.12 months. It can take a year if you start too young. If you only care when completion happens, then there's no point in starting earlier than 27 months.
To potty train: 2 ways.
Parenting enforcing a time
Laissez faire: just let it happen
The bottom line: do what works for your kid
Discipline
Education is about the child and not the parent. Discipline should serve the purpose of creating happy, healthy productive adults. Parenting/discipline programs involve some key ideas:
Children are not adults.
Don't get angry, don't yell, don't hit.
Control parent's anger
There's no explanation why tantrums happen, don’t go crazy trying to understand tantrums.
Use:
Incentives - humans have a super response to incentives, positive or negative. Prompt rewards work better than delayed ones.
Consistency and commitment - when parenting, it is useful to be predictable in order for children to model your behavior better. Also, when you say something will happen as a consequence, stick to your word.
Approaches like 1,2,3 Magic are proven to work through research. Spanking has negative consequences, mid and long term. Spanking increases behavioral problems later. There is no evidence that spanking improves behavior.
Discipline should be reserved to bad behavior Which means you have to learn to live with annoying kid attitudes.
Education
Reading to your child has positive correlation with later reading tests. Studies showed that being read to increases the activity in areas of the brain responsible for narrative processing. Benefits are higher with more interactive reading. Like asking open ended questions during a story.
Preschool
3 types:
Montessori - development of fine motor skills. Touch things as means to understand them.
Reggio Emilio - Emphasis on play
Waldorf - play and art.
Internal politics
Children can create tension in a marriage. Women seem less happy with their marriages after kids.
"Parenthood hastens marital decline"
The two biggest culprits to low happiness after kids:
Asymmetrical chore allocation
Sex (or lack-of)
Women do more chooses This creates more leisure time for men which women resent.
Parents also have have less sex. Parents who were happy before kids or that had planned pregnancies have smaller declines and faster rebounds.
Sleep is very important. Marriage checkups might work.
Conclusion
Remember to try to enjoy the ride. Little kids have little problems. Big kids have less problems but larger.
The best parenting advice the author was given when she asked about a particular problem to a pediatrician:
Just try not to think about that
Not 100% sure this is something that happens both in the US and EU. Something to discover in the next few months.